The present invention relates to vinylidene chloride polymers and, more particularly to vinylidene chloride polymers which are dispersible in nonsolvents for such polymers.
Halogenated compounds, such as chlorinated polyethylenes, crosslinked copolymers of vinyl halides, bromophenols, vinylidene chloride polymers, and the like, have long been used as additives for polymeric materials to provide enhanced flame-retardancy. Typically, the object in this art has been to achieve such flame-retardancy without significantly decreasing other beneficial properties of the base polymeric material.
On the other hand, a great deal of art has also been developed on the incorporation of high molecular weight polymer additives in polymeric materials to enhance properties other than flame-retardancy. With respect to polyurethane foam materials in particular, it is known that the load-bearing properties can be improved by using additives such as aqueous elastomer latices, vinyl aromatic polymers, and film-forming polymers having radicals reactive with the isocyanate component of the foam. Generally, this art has required the use of a further additive to provide enhanced flame-retardancy.
It would be highly desirable to have a polymer additive which could be incorporated in polyurethane foam materials to provide both improved flame-retardancy and enhanced load-bearing properties.
Accordingly, it is a primary object of the present invention to provide such polymer additive. More specifically, it is an object of the present invention to provide such an additive in the form of a vinylidene chloride polymer powder that can be dispersed in a polyol used to prepare the polyurethane foam materials.
A more general object of the present invention is to provide a vinylidene chloride polymer powder which can be dispersed in a nonsolvent for vinylidene chloride polymers and thereafter used to prepare polymeric materials having enhanced physical properties.